求助贴:mfc串口上位机发送数据需要加两个字节的crc16校验

[况几]

crc16校验的算法代码有，可是不会用。 目的:是需要把前14个字节的数据(十六进制)算出两个字节的crc16校验(十六进制)，然后一起发送到下位机。代码是c++ mfc。 新手一枚，头疼了好久，自己也百度了好久，就是不会写，希望大神可以给个参考代码。或者指点我一下，谢谢~

[这不是鸭头]

/***** crc16.h *****/
//Tested
#define CRC16_DNP	0x3D65		// DNP, IEC 870, M-BUS, wM-BUS, ...
#define CRC16_CCITT	0x1021		// X.25, V.41, HDLC FCS, Bluetooth, ...

//Other polynoms not tested
#define CRC16_IBM	0x8005		// ModBus, USB, Bisync, CRC-16, CRC-16-ANSI, ...
#define CRC16_T10_DIF	0x8BB7		// SCSI DIF
#define CRC16_DECT	0x0589		// Cordeless Telephones
#define CRC16_ARINC	0xA02B		// ACARS Aplications

#define POLYNOM		CRC16_XXX   // Define the used polynom from one of the aboves

// It calculates the new crc16 with the newByte. Variable crcValue is the actual or initial value (0).
unsigned int crc16(unsigned int crcValue, unsigned char newByte);

/***** crc16.c *****/

#include "crc16.h"

unsigned int crc16(unsigned int crcValue, unsigned char newByte) 
{
	unsigned char i;

	for (i = 0; i < 8; i++) {

		if (((crcValue & 0x8000) >> 8) ^ (newByte & 0x80)){
			crcValue = (crcValue << 1)  ^ POLYNOM;
		}else{
			crcValue = (crcValue << 1);
		}

		newByte <<= 1;
	}
  
	return crcValue;
}

/***** EXAMPLE *****/

unsigned int exampleOfUseCRC16 (unsigned char *Data, usigned char len){

	unsigned int crc;
	unsigned char aux = 0;

	crc = 0x0000; //Initialization of crc to 0x0000 for DNP
	//crc = 0xFFFF; //Initialization of crc to 0xFFFF for CCITT

	while (aux < len){
		crc = crc16(crc,Data[aux]);
		aux++;
	}

	return (~crc); //The crc value for DNP it is obtained by NOT operation

	//return crc; //The crc value for CCITT
}

[况几]

引用 1 楼 熊猫党团委副书记的回复:

/***** crc16.h *****/
//Tested
#define CRC16_DNP	0x3D65		// DNP, IEC 870, M-BUS, wM-BUS, ...
#define CRC16_CCITT	0x1021		// X.25, V.41, HDLC FCS, Bluetooth, ...

//Other polynoms not tested
#define CRC16_IBM	0x8005		// ModBus, USB, Bisync, CRC-16, CRC-16-ANSI, ...
#define CRC16_T10_DIF	0x8BB7		// SCSI DIF
#define CRC16_DECT	0x0589		// Cordeless Telephones
#define CRC16_ARINC	0xA02B		// ACARS Aplications

#define POLYNOM		CRC16_XXX   // Define the used polynom from one of the aboves

// It calculates the new crc16 with the newByte. Variable crcValue is the actual or initial value (0).
unsigned int crc16(unsigned int crcValue, unsigned char newByte);

/***** crc16.c *****/

#include "crc16.h"

unsigned int crc16(unsigned int crcValue, unsigned char newByte) 
{
	unsigned char i;

	for (i = 0; i < 8; i++) {

		if (((crcValue & 0x8000) >> 8) ^ (newByte & 0x80)){
			crcValue = (crcValue << 1)  ^ POLYNOM;
		}else{
			crcValue = (crcValue << 1);
		}

		newByte <<= 1;
	}
  
	return crcValue;
}

/***** EXAMPLE *****/

unsigned int exampleOfUseCRC16 (unsigned char *Data, usigned char len){

	unsigned int crc;
	unsigned char aux = 0;

	crc = 0x0000; //Initialization of crc to 0x0000 for DNP
	//crc = 0xFFFF; //Initialization of crc to 0xFFFF for CCITT

	while (aux < len){
		crc = crc16(crc,Data[aux]);
		aux++;
	}

	return (~crc); //The crc value for DNP it is obtained by NOT operation

	//return crc; //The crc value for CCITT
}

谢谢，那这个在mfc上位机通信中怎么用这个写好的crc16呢？通过这个得到第15,16字节的数值，跟前边要发送的数值连接起来一起发送下去呢？

[zgl7903]

发送前追加2字节校验即可

void SendData(const void *pSrcData, int iSrcLen)
{
  BYTE *sndData = new BYTE [ iSrcLen + 2];
  int iDataLen = 0;
  memcpy(sndData + iDataLen, srcData,  iSrcLen); //复制原始数据
 iDataLen += iSrcLen ;
  WORD wcrc = crc16(srcData,  iSrcLen); //CRC校验 
  sndData[ iDataLen ++] = HIBYTE(wcrc); //CRC高字节
  sndData[ iDataLen ++] = LOBYTE(wcrc); //CRC低字节
  
  DWORD dwWritten=0;
  WriteFile(hComm, sndData, iDataLen, &dwWritten, NULL);
  
  delete [] sndData; 
}